1. Field of the Invention
The present invention is related to a structure of signal line, and especially to a structure of signal line with high strength that renders the line itself not to deform when being bent; it is suitable particularly for use in signal transmission lines such as those for horns, power lines or the like.
2. Description of the Prior Art
In a conventional signal line such as that shown in FIG. 1, conductors xe2x80x9cAxe2x80x9d are enveloped in a PVC (or PE) insulation layer xe2x80x9cBxe2x80x9d to be entangled with another conductor enveloped in the PVC (or PE) insulation layer xe2x80x9cBxe2x80x9d, then a filler layer xe2x80x9cCxe2x80x9d is used to envelop the insulation layer xe2x80x9cBxe2x80x9d. The filler layer xe2x80x9cCxe2x80x9d is added thereover with a knitted metallic obscuring layer xe2x80x9cDxe2x80x9d which is further enveloped completely in a PVC (or PE) coating layer xe2x80x9cExe2x80x9d. The gap in such an improved electric line are totally filled by the filler layer xe2x80x9cCxe2x80x9d which envelops the PVC (or PE) insulation layer xe2x80x9cBxe2x80x9d therein, this can reduce transient pulsing, and can reduce the danger of melting of the PVC (or PE) insulation layer xe2x80x9cBxe2x80x9d when loading is increased. Although such a structure can get improvement on the defect of having a gap of the conventional signal line, it still can not completely get rid of the main defect of mutual interference induced during transmission by contact of the two conductors thereof too close to each other.
Referring to FIG. 2 showing another conventional structure of signal line, the signal line is made a tube body 1 from a PVC insulation layer, the inner wall of the tube body 1 is provided with two hollow thin pipes 2 with a space 4 therebetween, the two hollow thin pipes 2 are both extended therein a rectangular conductor 3 for effectively getting rid of the defect of mutual interference induced by being too close to each other of the two conductors 3. However, by virtue that there are only two hollow thin pipes 2 in the tube body 1, and the rest space 4 is empty, the strength of the tube body 1 is not enough, the space 4 (distance) between the two conductors 3 may change by bending, thereby the two conductors 3 not only mutually interfere with each other again, but also signal transmission may be influenced by deformation of the two conductors 3 induced by pressing on the weak hollow tube body 1. In this view, the conventional structure of signal line is not ideal either.
Therefore, the motive in study and development of the present invention is to improve on the defects resided in the conventional structures of signal line, in order to provide 100% obscuring, to minimize the degree of mutual interference, to increase the strength of the signal line to avoid deformation of the structure of the signal line due to bending.
The primary object of the present invention is to increase the strength of a signal line to avoid deformation of the structure of the signal line due to bending.
The secondary object of the present invention is to minimize the degree of mutual interference and thereby to provide a signal line with 100% obscuring,
To achieve the above stated objects, the present invention is comprised of a core portion, a middle filler layer, an obscuring layer and an outer coating portion. The core portion has at least a rectangular conductor which is enveloped by an insulation tape; the obscuring layer has at least a knitted metallic obscuring layer; the outer coating portion has at least a layer made of polyvinyl chloride composition; and the middle filler layer is comprised of a plurality of hollow tubes. The core portion is tangled with the middle filler layer to make the line stronger in addition to being flexible, so that the line will not have the core portion damaged when it is bent to deform, plus the obscuring function of the obscuring layer, the degree of mutual interference can be reduced to the minimum.
The present invention will be apparent after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.